SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/73468
never assume you have adequate pressure—it's a critical design element that cannot be taken for granted." So what exactly constitutes "high water pressure?" That depends on the sprays and ro- tors in use on a particular field. The vast major- ity of sports field playing surfaces are irrigated with larger rotors that have an accordingly larger distance of throw. "Most of my sports field customers irrigate their playing surfaces with rotors having a throw radius of 39 to 81 feet, or a throw radius of 39 to 64 feet," Dim- mick said. "Due to their greater throw radius, the appropriate operating pressure for those ro- tors will be higher than, say, a rotor used in tighter areas, such as the areas between first and third bases and the fence line, or behind home plate and the backstop on a baseball field. The rotors used on the field itself may have a speci- fied operating pressure range of anywhere from 30 to 100 psi; the smaller rotors or sprays used elsewhere will typically operate at a pressure range of 25 to 65 psi. However—just because your water pressure falls into the product's spec- ified range doesn't mean that the rotor or spray is operating at maximum efficiency. It's impor- tant to check product specs or ask your local ir- rigation professional to determine the optimal pressure for your particular brand and model." According to Dimmick, sprays typically is specifically designed for use with commercial valves like those used in sports field irrigation systems. The module threads underneath the solenoid and adapter, effectively optimizing inlet pressure for all the rotors or sprays in an entire zone. However, while it's certainly better than not regulating pressure at all, regulating pressure at the valve may not be as accurate as using a pressure regulating swing joint or a sprinkler with in-stem pressure regulation. This is because the dynamic pressure—pressure while water is in motion—is constantly chang- ing. When regulating pressure at the head rather than at the valve, the discharge pressure will be identical at each head, causing the heads to discharge the same amount of water. "High or fluctuating water pressure can ob- viously have a tremendous impact on any irri- gation system's efficiency and effectiveness," Dimmick said. "Given the higher prevalence of watering restrictions and rising water prices throughout the country, pressure regulation is a topic that deserves attention both on and off the field." ■ have an optimum inlet pressure of 35 psi and smaller rotors operate their best at 45 psi. To help customers with high or fluctuating water pressure, Rain Bird has developed spray and rotor models with what the company refers to as "Flow Optimizer Technology." Inlet pres- sures up to 100 psi are effectively managed by integrated pressure-regulating stems (PRS) and ensure that these products always operate at optimum pressure levels. These particular products are very useful when irrigating areas off the field. But what about those larger rotors that water football, baseball or soccer fields? There are other ways to alleviate the problems associated with high or fluctuating water pressure. Pressure-regulat- ing swing joints, for example, can also control and maintain a preset rotor inlet pressure. Like a pressure-regulating stem built into smaller ro- tors and sprays, these swing joints ensure opti- mal droplet size and eliminate misting, resulting in improved uniformity and reduced water consumption. They can also be used to provide the same pressure to each rotor on a zone in applications where high flow rates re- sult in significant friction losses or where there are elevation changes. It's also possible to regulate water pressure at the valve using a pressure-regulating module like Rain Bird's PRS Dial. This type of product www.stma.org SportsTurf 31